Railway traffic controlling apparatus



June 10, 1941; 5.1-; OHAGQAN 2,244,797

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed July 28, 1939 l ENTOR 591 17627 OHagan HIS ATTORNEY Patented June 10, 1941 RAILWAY TRAFFIC CONTROLLING APPARATUS Bernard E. OHagan, Swissvale, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application July 28, 1939, Serial No. 287,109

7 Claims.

My invention relates to railway traflic controlling .apparatus, and has particular reference to the organization of such apparatus into railway signaling systems of the type in which railway signal-s which are normally dark are approach lighted or controlled to an illuminated condition in response to trafiic conditions adjacent the signal location.

An object of my present invention is the provision of novel and improved means for establishing approach lighting of railway signals through the medium of train detecting devices, such for example, as track instruments, which operate independently of track circuits.

Another object is to establish approach lighting of signals by novel and improved means relatively economical to install and maintain, and requiring a minimum of apparatus.

A further object is to establish approach lighting of signals by novel and improved means in which track relays are combined with train detectors to provide a system controlled in part by track relays and in part by train detectors.

Other objects and advantages of my invention will appear from the following description.

Apparatus embodying my invention is particularly useful in connection with signals controlling trafilc in unbonded stretches of track, such for example, as industrial spurs, passing sidings, etc., in which the cost of installation and maintenance of track circuits prohibits the use of the ordinary track circuit control of approach lighting signals. By virtue of the simple and economical apparatus embodying my inventlon, and its reliable characteristics in operation, signals may economically be approach lighted in response to railway traflic moving in unbonded stretches of track, thereby obtaining operating advantages heretofore believed impracticable to I obtain.

I shall describe two forms of apparatus embodying my invention and shall thenpoint out the novel features thereof in claims.

In the accompanying drawing, Fig. l is a diagrammatic view of a preferred form of apparatus embodying my invention shown applied to an unbonded siding connecting with a track-circuited stretch of track. Fig. 2 is a diagrammatic view of a modified form of the apparatus shown in Fig. 1, and which also embodies my invention.

Similar reference characters refer to similar parts in each of the two views.

Referring to Fig. l, the reference characters I and la designate the track rails of 'a stretch of railway divided by means of the usual insulated suitable distinguishing sufiix, connected across the track rails at the other end of the section. An unbonded siding PS (shown :as a passing siding) is located paralleling section 3-4 and is connected by means of a turnout which includes a track switch W, with section 3-4 near its righthand end as viewed in the drawing. Trailic movement in siding PS normally is in the single direction indicated by an arrow in the drawing or from left to right in the siding. The rails of siding PS are insulated from the rails of the turnout by means of rail joints 2 positioned at the fouling point of the turnout, but the rails of the turnout intermediate such insulated joints and the rails of section 3--4 are included in the track circuit of section 3-4 in the usual and wellknown manner.

A signal S4 is positioned adjacent the junction of sections 3-4 and 4-5 for governing traific moving over the rails l and la from left to right, as viewed in the drawing. The movement of traffic from the siding into the stretch also is guided to some extent by signal S4, inasmuch as a train on the siding normally will not move into the stretch preparatory to entering section 4-5 unless signal S4 displays an indication permitting a movement of traflic into that section.

Signal S4 may take any one of several Wellknown forms, but as herein shown is a three-indication color light signal comprising a red lamp R, a yellow lamp Y and a green lamp G, which lamps when illuminated indicate "stop, approach and clear, respectively. Signal S4 normally is dark, and is approach lighted in response to trafi'ic conditions adjacent the signal to control the signal to a lighted indication, the particular indication displayed by signal S4 when illuminated being determined by control means of the usual form, controlled by traflic conditions in advance of the signal. These control means form no part of my present invention, and are shown conventionally in the drawing as contacts Ill-10b, H-l|a and I2-l2a, which bear the legend traffic controlled contacts and which are controlled in the usual manner by apparatus (not shown in the drawing) responsive to traffic conditions in advance of the signal, to determine the particular indication to be displayed by signal S4 when illuminated. As shown, contact Il0b is interposed in an obvious energizing circuit for lamp R of signal S4, so that when contact Hl-l 0b is closed, signal S is conditioned to display its stop indication when illuminated. Contact I |l la is interposed in an obvious energizing circuit for lamp Y of signal S4, while contact 12-120. is interposed in an obvious energizing circuit for lamp G for signal S4, with the result that signal S4 is conditioned to display its approach indication when contact ll-l la is closed, and its clear indication when contact lZ-I 2a is closed.

The reference character L4 designates an approach lighting relay associated with signal S4. Relay L4 normally is energized over a circuit which may be traced from one terminal B of a suitable source of current, such as a battery not shown in the drawing, through .front contact 13-1301. of relay TR5. front contact I i-Ma of relay TBA and the winding of relay L4 to the other terminal C of the source of current, and relay L4 controls over its back contact I 5-451) the supply of energy to the control energizin cir cuits of the signal lamps of signal S4, as is readily apparent from an inspection of the drawing. Signal S4, therefore, normally is non-illuminated but is controlled to an illuminated condition whenever section 3-4 or 45 :is occupied and relay L4 is released, the particular indication displayed by signal S4 under the above conditions being determined in accordance with the positions of trafiic control contacts llll!lb, ll--I la and l2-l 2a, which contacts as pointed out previously are controlled in response to traiiic conditions in advance of the signal. It follows that signal S4 is approach lighted in the usual manner in response to traffic conditions adjacent the signal.

Signal S4 also is approach lighted in response to a train occupying siding PS by means of a second approach lighting relay L ta which controls over its back contact Iii-461) the supply of energy to the control energizin circuits of signal S4, as is readily apparent from an inspection of thedrawing. Relay L la is controlled by meansresponsive only to traffic movements in siding. PS, to cause the release of relay L la when a train approaches the leaving end of the siding,

thereby establishing approach control of signal S4. which guides the movements of traflic leavin the passing siding.

The means controlling relay Ltd as shown includes a train detector, such for example, as a track instrument M operatively associated with the rails of siding PS, and a control relay MS controlled by instrument M and controlling an energizing circuit for relay L la, which circuit may be traced from terminal B through front contact I3!3a of relay TR5, front contact I'|-I'|a of relay MS, and the winding of relay L401. to terminal C. Track instrument M may take any one of many well-known forms of track instruments of the type characterized by the provision of a normally closed contact which is operated to an open position in response to the actuation of the instrument by the wheels of a moving train. For example, instrument M may be of the form shown in United States Letters Patent No. 1,834,077 issued on December 1, 1931 to A. J. Sorensen.

Relay MS, above referred to, normally is energized over a stick circuit which passes from terminal B' through the normally closed contact of instrument M, the winding of relay MS and its front contact Iii-ma to terminal 0. Relay MS is provided with a pick-up circuit which includes the source of current, the contact of track instrument M, the winding of relay MS and back contact l 9-491) of relay TRE. It is readily apparent, therefore, that relay MS normally is energized,

and is released whenever a train operating on' siding PS approaches the leaving end of the siding and actuates instrument M, and that relay MS remains released until relay TBS is released in response to traffic conditions in advance of signal S4 (as for example when the train on siding PS enters section fi.-5), to reestablish the pickup circuit for relay MS. It follows from the foregoing that approach lighting of signal S4 located at the leaving end of passing siding PS is effected by a train moving along the siding toward its leaving end.

It should be noted that when the train on siding PS enters section 3-4 over the turnout, relay L4 is also released due to the shunting of track relay TR l, to establish the normal approach lighting circuit for signal S 5. Both relays L4 and Lea are picked up, however, when the train vacates section 4-5 and their respective energizing circuits are completed at front contact l3--l 3a of relay TR5.

An advantage of apparatus embodying my invention is that such apparatus provides approach lighting for signals located at the leaving end of a passing siding without requiring track circuits or bonded rail sidings. The apparatus embodying my invention is relatively economical and simple to install and maintain, and as a result may profitably be employed to obtain operating advantages of having signals approach lighted by trains on unbonded sidings or stretches of track, which advantages heretofore have been thought impracticable to obtain.

In Fig. 1, if a train moves through siding PS against the normal trafiic direction, or from right to left in the siding, the actuation of instrument M causes the release of relay MS and consequent lighting of signal Se until such time assection 45 becomes occupied and relay TR5 is released to establish the pick-up circuit of relay MS. Siding PS of Fig. 1 accordingly is adapted for use for traflic operating in but the normal direction of traffic, or from left to right in the siding. For such trafic, it can be seen that signal S4 is controlled to its lighted indication when instrument M is actuated to causethe release of relay MS, and when the train continues its movement through sections 34 and 45, the shunting of relay TR5 establishes the pick-up circuitof relay MS with the result that when section 45 is vacated, relay Lia also picks up to control signal S4 to its normally non-illuminated condition.

Referring now to Fig. 2, a modification of the apparatus of Fig. 1 is shown which permits traiiic movements in either direction in passing siding PS. In Fig. 2, the apparatus is substantially similar to the apparatus described in connection with Fig. 1, except that three track instruments Ml,

M2 and M3 are employed, and another relay MSR also is employed. Track instruments MI and M2 are interposed in series in the pick-up and stick circuits of relay MS, instrument MI being located in the rear of the fouling point of the passing siding, and instrument M2 being located near the fouling point. Thus, in the event that section 45 is occupied during the interval that a short train, operating in passing siding PS, actuates instrument Ml so that after the train clears instrument Ml, the pick-up circuit of relay MS is established through the closed contact of instrument 'MI and back contact I9--l9b of relay TR5, the train can obtain approach lighting of signal S4 after section 4-5 becomes vacated by pullin over the second track instrument M2 located adjacent the fouling point of the siding, thereby releasing relays MS and L ia to control signal S4 to its lighted indication.

Instrument M3 is located along the track rails of passing siding PS to the left of the location of instrument MI, and instrument M3 controls relay M3R over an obvious circuit which includes the normally closed contact of instrument M3. Relay M3R controls over its back contact 202Eb a second pick-up circuit for relay MS, which circuit includes the source of current, the contacts of instruments MI and M2, in series, the winding of relay MS and back'contact 20-401) of relay M3R. The second pick-up circuit of relay MS prevents prolonged unnecessary operation of signal S4 in the event that a train operates from right to left in the siding. That is to say, for train movements from right to left in passing siding PS of Fig. 2, instruments MI and M2 are actuated by the train to interrupt the stick circuit for relay MS, thereby causing the release of relays MS and Lia. and controlling signal S4 to its lighted condition. Further operation of the train toward the left, however, results in instrument M3 being actuated and in the release of relay M3R, with the result that after the train clears instruments MI and M2, the pick-up circuit for relay MS is reestablished over back contact 20-201 of relay M3R and relay MS picks up to also pick up relay Lda, whereupon signal S4 is controlled toits darkened condition. It follows that the apparatus of Fig. 2 is adapted for use in connection with a passing siding over which traffic operates in both directions.

It should be pointed out that a further modifi cation (not shown) of the apparatus of Figs. 1 and 2 may be provided to establish approach control of a signal solely through the medium of train detectors. For example, a signal might be positioned along siding PS intermediate instruments Ml and M3 of Fig. 2. Then, by utilizing the apparatus of Fig. 2 but dispensing with the pick-up circuit of stick relay MS controlled by track relay TR5, approach control of the signal along siding PS can be established directly by stick relay MS for railway trafiic moving over the siding from right to left. Under the above conditions, whenever instrument MI or M2 of Fig. 2 is actuated, the stick circuit of relay MS is interrupted and relay MS releases to control the signal to its illuminated condition. After the train passes the signal, instrument M3 then would be actuated to release relay M3R, so that when the train clears instruments MI and M2 located in the rear of the signal, a pick-up circuit for relay MS is established and relay MS accordingly picks up to control the signal to its normally dark condition.

An advantage of the modification just described is that approach control of a signal is established entirely independently of track circuits, and hence such system is particularly well adapted for use on non-track-circuited stretches of track to provide approach control of signals governing traffic in such stretches.

Although I have herein shown and described only two forms of railway traflic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is':'

1. In combination, a stretch of railway track provided with an insulated track section having a track relay, a normally non-illuminated signal for controlling trafiic in said section, two track instruments located spaced apart along said stretch in the rear of said signal, each said track instrument having a normally closed contact which is operated to an open position in response to actuation by a moving train, a stick relay normally energized over a stick circuit including the normally closed contact of the one of said two track-instruments located nearer said signal, means controlled by said stick relay for controlling said signal to its illuminated condition, a first pick-up circuit for said stick relay controlled by the contact of said one track instrument and by said track relay, and a second pickup circuit for said stick relay controlled by the respective contacts of each of said two track instruments in such manner that a train receding from said signal past said two track instruments establishes said second pick-up circuit.

2. In combination with a stretch of railway track provided with an insulated track section having a track circuit including a track relay, a normally non-illuminated signal for controlling traffic in said section, means responsive to traffic conditions in said stretch in the rear of said section'for controlling said signal to its illuminated condition, a siding connected with said stretch in the rear of said signal, two track instruments located spaced apart along said siding, each of said two track instruments having a normally closed contact which is operated to an open position in response to actuation by a moving train, a stick relay normally energized over a stick circuit including the contact of the one of said two track instruments located nearer said signal, a first pick-up circuit for said stick relay controlled by the contact of said one track instrument and by said track relay, a second pick-up circuit for said stick relay controlled by the respective contacts of each of said two track instruments in such manner that a train receding from said signal in said siding establishes said second pickup circuit, and an approach lighting relay for said signal controlled by said stick relay.

3. In combination with a stretch of railway track provided with an insulated track section having a track circuit including a track relay, a

; normally non-illuminated signal for controlling traffic in said section, means responsive to trafiic conditions in said stretch in the rear of said section for controlling said signal to its illuminated condition, a siding connected with said stretch in the rear of said signal, three track instruments located spaced apart along said siding, each of said track instruments having a normally closed contact which is operated to an open position in response to actuation by a moving train, a stick relay, a first pick-up circuit for said stick relay controlled by the [track instrument most remote from said signal and including in series the contacts of the other two track instruments, said stick relay normally being energized over a stick circuit which includes in series the contacts of said other two track instruments, a second pick-up circuit for said stick relay controlled by said track relay and including in series the contacts of said other two track instruments, and an approach lighting relay for said signal controlled by said. stick relay.

4. In combination with a stretch of railway track provided with an insulated track section having a track circuit including a track relay, a normally non-illuminated signal for controlling traflic in said section, a siding connected with said stretch in the rear of said signal, a track instrument located along said siding and having a normally closed contact which is operated to an open position in response to actuation by a moving train, a stick relay normally energized over a stick circuit including the normally closed contact of said track instrument, means controlled by said stick relay for controlling said signal to its illuminated condition, means controlled by said track relay for establishing a first pick-up circuit for said stick relay, and other means responsive to traffic receding from said signal in said siding for establishing a second pick-up circuit for said stick relay.

5. In combination with a stretch of railway track and a signal associated with said stretch, two track instruments located spaced apart along said stretch to one side of said signal, each of said instruments being operatively connected with a rail of said stretch and having a contact operable from a normal to an operated condition in response to train movements on said stretch adjacent its location, a stick relay normally energized over a stick circuit controlled by the normally closed contact of the one of said two track instruments adjacent said signal, a pick-up circuit for said stick relay controlled by both of said track instruments and completed when the contact of the other track instrument is in its operated condition and the contact of the said on track instrument is in its normal condition, and means controlled by said stick relay for governing said signal.

6. In combination with a stretch of railway track and a signal associated with said stretch, two track instruments located spaced apart along said stretch to one side of said signal, each of said instruments being operatively connected with a rail of said stretch and having a contact operable from a normal to an operated condition inresponse to train movements on said stretch adjacent its location, a stick relay normally energized over a stick circuit controlled by the one of said two track instruments adjacent said signal, a first pick-up circuit for said stick relay controlled by contacts of'both of said two track instruments and completed when the contact of said one track instrument is in its normal condition and the contact of the other \track instrument is in its operated condition, a second pick-up circuit for said stick relay controlled by said one track instrument and by traffic conditions on said stretch on the other side of said signal, and means controlled by said stick relay for governing said signal.

7. In combination with a stretch of railway track provided with an insulated track section and having a signal positioned adjacent one end of said section, a track relay for said section, two track instruments located spaced apart along said stretch exterior said section adjacent said one end, each of said track instruments being operatively connected with a rail of said stretch and having a contact operable from a normal to an operated condition in response to train movements on said stretch adjacent its location, a stick relay normally energized over a stick circuit controlled by the one of said two track instruments adjacent said signal, a first pick-up circuit for said stick relay controlled by said one track instrument and by said track relay, a second pick-up circuit for said stick relay controlled by both of said track instruments and completed when the contact of said one track instrument is in its normal condition and the contact of the other track instrument is in its operated condition, and means controlled by said stick relay for governing said signal.

BERNARD E. OHAGAN. 

